1. Field of the Invention
This invention relates to devices and methods for endoscopically manipulating sutures during surgical procedures. More particularly, this invention relates to devices and methods for endoscopically suturing tissue.
2. Description of the Prior Art
Endoscopic suturing techniques and instruments have been developed in order to facilitate the suturing of tissue during endoscopic surgical procedures. The term "endoscopy" encompasses arthroscopy, laparoscopy, hysteroscopy, etc. and endoscopic surgery involves the performance of surgical procedures within a patient's body through small openings as opposed to conventional open surgery through large incisions. Access to a surgical work site within a patient's body is normally provided through one or more portals formed directly in the patient's body or through one or more cannulas inserted into the patient's body through small incisions. A chosen surgical procedure is carried out by a surgeon through the use of elongated instruments inserted through these cannulas and it often becomes necessary to suture selected tissue at the surgical work site.
Since the work site is only accessible through a small portal or cannula and since it is very difficult to tie sutures within the body, various devices and techniques have been developed to enable the surgeon to tie sutures endoscopically. For example, some procedures enable the surgeon to pass suture material through selected tissue, form a surgical knot extracorporeally and then move the knot with a knot pusher through the portal or cannula into position adjacent the desired tissue to be sutured. Some instruments used to pass the suture incorporate a hollow needle provided with some means to guide suture through the tissue pierced by the needle.
The procedure typically used to tie sutures endoscopically involves retrieving the end of the suture after it has been passed through the tissue site to be sutured. The retrieved suture end can then be manipulated with the other suture end to tie a knot. The retrieval of suture is sometimes accomplished by simply grasping it with regular forceps or other graspers or specific suture retrieval forceps having a suture capturing aperture formed at the distal tip when the forceps jaws are closed. Some suture retrievers are simply loops which extend from the tip of an elongated tube and which can be closed upon a suture passed through the loop. U.S. Pat. No. 5,250,054 (Li) discloses a suture retriever in the form of a knot tying device having an elongated inner rod slidably situated within an elongated outer sleeve. The distal end of the inner rod is provided with a pre-formed bend and the tip has a crochet-type hook to retrieve suture. These devices, however, require a separate needle to suture tissue. Therefore, to facilitate the process the needle and grasper are sometimes combined in one instrument. For example, a known prior art elongated needle/grasper which facilitates endoscopic suturing is described in U.S. Pat. No. 5,312,432 (Trott) entitled "Endoscopic Suturing Needle", assigned to the assignee hereof and incorporated herein by reference. This endoscopic suturing needle comprises an elongated tubular housing having a needle at the distal tip and a trigger mechanism to advance and retract the needle relative to the housing. The needle is pointed and flat and has a recess provided at a predetermined distance proximal to the needle tip. When the needle is fully retracted relative to the housing, the recess provides an opening to capture suture material therein. This allows the needle to either push or pull suture through selected tissue. Repeated manipulation of the suture can thus create the desired surgical stitch.
Another type of suturing needle is disclosed in U.S. Pat. No. 5,222,977 (Esser) in which the needle tip is stationary and a movable slide is provided to open and close a suture receiving recess spaced a predetermined distance from the needle tip. A similar mechanism is shown in German Patent No. 2532242 which discloses a cylindrical needle having a reciprocating internal slide member to open and close a recess spaced from the needle tip.
Another known suture retrieval instrument comprises a curved hollow tube having a distally extending suture snare. The device, known as the Ideal Suture Grasper marketed by Innovasive Devices, Inc., 100B South Street, Hopkinton, Mass. 01748, requires two components to capture suture and is only able to retrieve suture that is in line with the distal tip.
The means by which a strand of suture material can be grasped or retrieved with the prior art devices is limited because all of the known suture needle/retrieval devices have suture snaring means which are situated on or in line with the needle body. Consequently, the device must be manipulated close enough to the suture to guide the suture into a suture receiving recess so the recess can be closed to retain the suture to enable its manipulation. In an endoscopic procedure it is often difficult to manipulate the suturing needle close enough to the suture to accomplish this. Accordingly, it is an object of this invention to provide an endoscopic suturing needle which enables a surgeon to retrieve a suture spaced some distance laterally from the needle, without having to reposition the needle so as to place the suture in the recess or grasping structure.
It is also an object of this invention to produce an endoscopic suturing needle in which the suture snaring structure can be automatically deployed away from the axis of the needle tip in order to increase the volume of space within which the suture may be present and still be grasped.
It is also an object of this invention to provide a suture retriever for endoscopically retrieving suture material without the necessity of guiding the retriever as close to the suture as required by prior art devices.
It is another object of this invention to provide a suture retriever having an extended lateral reach in order to retrieve suture within a larger area than prior art devices.
It is still another object of this invention to provide a simplified endoscopic needle and suture retriever combination having an extended lateral reach in order to retrieve suture within a larger area than prior art devices.